Extendable billiard cue

ABSTRACT

An extendable billiard cue is disclosed to include a shaft, a butt detachably fastened to the shaft, a sleeve, which is embedded in the butt remote from the shaft and has two positioning devices near the two distal ends, a pull bar, and a stem, which has one end fixedly connected to the pull bar and the other end axially movably inserted into the sleeve and fixedly provided with a positioning device selectively engageable to one of the positioning devices of the sleeve to lock the billiard cue in the extended (first length) position or received (second length) position. After disconnection of the shaft from the butt, the detached billiard cue is receivable in a cue bag.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a billiard cue and more particularly, to an extendable billiard cue.

2. Description of Related Art

FIG. 1 is an exploded view of a conventional billiard cue. As illustrated, the billiard cue 10 is comprised of a butt 13 and a shaft 15. The shaft 15 has a female screw 151 axially provided at the rear end. The butt 13 has a male screw 131 axially extending from the front end for threading into the female screw 151. When not in use, the butt 13 is disconnected from the shaft 15.

The aforesaid billiard cue 10 has a fixed length. If the location of the white ball is deviated from the hitting position and the player cannot operate the billiard cue to strike the white ball in a normal driving posture, the player may have to fall flat on the pool table or to put a bridge on the pool table for supporting the billiard cue. Striking the white ball in either of the aforesaid two methods affects the striking accuracy.

In order to eliminate the aforesaid problem, an extension butt 17 may be used. The extension butt 17 has a front coupling hole 171 through which the extension butt 17 can be directly and detachably attached to the rear end of the butt 13 to extend the length of the billiard cue 10. However, the coupling hole 171 of the extension butt 17 wears quickly with use. When the coupling hole 171 of the extension butt 17 starts to wear, the connection between the extension butt 17 and the rear end of the butt 13 becomes unstable, and the extension butt 17 may vibrate relative to the billiard cue 10, affecting the striking accuracy. Further, the cue bag is designed to receive the shaft 15 and the butt 13 only, providing no extra room for accommodating the extension butt 17. Therefore, the extension butt 17 must be separately carried.

Therefore, it is desirable to provide a billiard cue that eliminates the aforesaid problems.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. According to one aspect of the present invention, the extendable billiard cue comprises a shaft, a butt, a sleeve, a stem, and a pull bar. The butt is detachably fastened to one end of the shaft, having a longitudinal chamber axially extending to one end thereof remote from the shaft. The sleeve is fixedly mounted inside the longitudinal chamber of the butt in a flush manner, having a front positioning device near a front end thereof and a rear positioning device near a rear end thereof. The pull bar has a locating hole at one end thereof. The stem is inserted into the sleeve and movable in and out of the sleeve between an extended position and a received position, having a front end fixedly fastened to the locating hole of the pull bar and a positioning device fixedly provided at a rear end thereof the positioning device of said stem selectively engageable to the front positioning device and rear positioning device of the sleeve to lock the stem to the sleeve in the extended position or the received position.

The invention further comprises a locating block fixedly mounted in the locating hole of the pull bar and adapted to affix the stem to the pull bar. The locating block has a screw hole fastened to the front end of the stem. Alternatively, the stem can be fastened to the locating block by a rivet joint, tenon-and-mortise joint, or any of a variety of conventional mounting techniques.

The invention further comprises a spring member mounted in the sleeve and adapted to impart an outward pressure to the stem. When the stem and the sleeve are locked, the push force of the spring member holds down the connection between the stem and the sleeve, preventing vibration of the extendable billiard cue.

Further, the stem has an index in front of the positioning device thereof for position indication. Through the index at the stem, the user knows if the stem is in the position engageable to the front positioning device of the sleeve.

Further, the pull bar has an index for position indication, and the butt has an index corresponding to the index of the pull bar for position indication.

Further, the positioning device of the stem comprises at least one stop block protruded from the periphery thereof. The front positioning device and rear positioning device of the sleeve each comprise at least two inside flanges inwardly protruding from an inside wall thereof. Further, screw joint or any of a variety of other equivalent positioning means may be used as a substitute for enabling the stem to be locked to the sleeve in the extended or received positions. An addition and addition devices may be inside the sleeve between the front positioning device and rear positioning device for locking the stem to the sleeve in one of a number of positions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a billiard cue according to the prior art.

FIG. 2 is an exploded view of an extendable billiard cue according to the present invention (the shaft excluded).

FIG. 3 is a sectional view of a part of the present invention, showing the extended status of the extendable billiard cue.

FIG. 4 is a schematic sectional view of the present invention, showing the stem disengaged from the front positioning device of the sleeve and moved inwards toward the inside of the sleeve.

FIG. 5 corresponds to FIG. 4, showing the stem received inside the sleeve, the pull bar attached to the butt.

FIG. 6 is an elevational view of the present invention, showing the extended status of the extendable billiard cue.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 2 and 6, an extendable billiard cue 20 in accordance with the present invention is shown comprised of a pull bar 30, a locating block 31, a stem 32, a spring member 33, a sleeve 34, a butt 40, and a shaft 50.

As shown in FIG. 2, the pull bar 30 has a locating hole 301 at one end, and an index 303 at the periphery. The locating block 31 has a screw hole 311. The stem 32 has a screw rod 324 at the front end 321, a positioning device 325 at the rear end 322, and an index 326 around the periphery behind the positioning device 325. The sleeve 34 has a front positioning device 341 at the front end, and a rear positioning device 342 at the rear end. The butt 40 has a longitudinal chamber 401 extending to the rear end thereof remote from the shaft 50, and an index 403 at the periphery adjacent to the end edge of the rear end. According to the present preferred embodiment, the index 326 of the stem 32 is a groove extending around the periphery of the stem 32; the index 303 of the pull bar 30 is a triangle sign directly printed on the periphery of the pull bar 30; the index 403 of the butt 40 is a triangle sign directly printed on the periphery of the butt 40. Further, the positioning device 325 of the stem 32 is comprised of two stop blocks projecting from the periphery of the stem 32 at two sides; the front positioning device 341 and rear positioning device 342 of the sleeve 34 each are comprised of two inside flanges symmetrically bilaterally protruding from the inside wall of the sleeve 34. The distance between the two inside flanges of 341 and 342 is greater than the width of the positioning device 325 of the stem 32 such that the positioning device 325 of the stem 32 can selectively set into engagement with the front positioning device 341 or rear positioning device 342 of the sleeve 34.

The assembly process of the present invention is outlined hereinafter with reference to FIG. 3 and FIG. 2 again. The locating block 31 is fixedly mounted in the locating hole 301 of the pull bar 30, and then the screw rod 324 of the stem 32 is threaded into the screw hole 311 of the locating block 31, and then the sleeve 34 is mounted in the longitudinal chamber 401 of the butt 40, and then the spring member 33 is sleeved onto the rear end 322 of the stem 32 and mounted with the rear end 322 of the stem 32 in the sleeve 34.

The use of the present invention is outlined hereinafter with reference to FIGS. 3˜5. The stem 32 can be pulled out of the sleeve 34 as desired. When the index 326 lays open to the outside of the sleeve 34 and the butt 40, the positioning device 325 of the stem 32 is in an engageable position relative to the front positioning device 341 of the sleeve 34. At this time, rotate the pull bar 30 in clockwise direction through 90-angles to force the positioning device 325 of the stem 32 into engagement with the front positioning device 341 of the sleeve 34, thereby locking the extendable billiard cue 20 in the extended condition and keeping the index 303 at the pull bar 30 in line with the index 403 at the butt 40. When wishing to retract the length of the extendable billiard cue, as shown in FIG. 4, rotate the pull bar 30 in counter-clockwise direction through 90-angles relative to the butt 40 to disengage the positioning device 325 of the stem 32 from the front positioning device 341 of the sleeve 34, allowing axial movement of the stem 32 with the pull bar 30 relative to the sleeve 34. When the pull bar 30 touched the butt 40, as shown in FIG. 5, the positioning device 325 of the stem 32 is in an engageable position relative to the rear positioning device 342 of the sleeve 34. At this time, rotate the pull bar 30 in clockwise direction through 90-angles to force the positioning device 325 of the stem 32 into engagement with the rear positioning device 342 of the sleeve 34, thereby locking the extendable billiard cue 20 in the received condition and keeping the index 303 at the pull bar 30 in line with the index 403 at the butt 40.

Referring to FIG. 6, the shaft 50 is detachably fastened to the butt 40 by, for example, a screw joint (not shown) to constitute the cue body of the billiard cue 20.

As indicated above, the stem 32 can be moved in and out of the sleeve 34 and selectively engaged with the front positioning device 341 or rear positioning device 342 of the sleeve 34, keeping the extendable billiard cue 20 in the extended or received condition. Therefore, the user can selectively set the extendable billiard cue 20 between two positions to fit different requirements. When the extendable billiard cue 20 is in the received condition, the shaft 50 can be detached from the butt 40, allowing the separated two parts to be received in a cue bag. Further, the spring member 33 is mounted inside the sleeve 34 and stopped between a part inside the butt 40 and the positioning device 325 of the stem 32 to impart an outward pressure to the stem 32. When the positioning device 325 of the stem 32 is kept engaged with the front positioning device 341 or rear positioning device 342 of the sleeve 34, the push force of the spring member 33 hold down the connection between the stem 32 and the sleeve 34, preventing vibration of the extendable billiard cue 20.

Although the present invention has been explained in relation to its preferred embodiments, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

1. An extendable billiard cue comprising: a cue body comprising a butt and a shaft, said butt having a longitudinal chamber axially extending to one end thereof remote from said shaft; a sleeve fixedly mounted inside the longitudinal chamber of said butt, said sleeve having a front positioning device near a front end thereof and a rear positioning device near a rear end thereof; a pull bar, said pull bar having a locating hole at one end thereof; and a stem inserted into said sleeve and movable in and out of said sleeve between an extended position and a received position, said stem having a front end fixedly fastened to the locating hole of said pull bar and a positioning device fixedly provided at a rear end thereof, the positioning device of said stem selectively engageable to the front positioning device and rear positioning device of said sleeve to lock said stem to said sleeve in one of said extended position and said received position.
 2. The extendable billiard cue as claimed in claim 1, further comprising a locating block fixedly mounted in said locating hole of said pull bar and adapted to affix said stem to said pull bar.
 3. The extendable billiard cue as claimed in claim 2, wherein said locating block has a screw hole.
 4. The extendable billiard cue as claimed in claim 1, further comprising a spring member mounted in said sleeve.
 5. The extendable billiard cue as claimed in claim 1, wherein said stem has an index for position indication.
 6. The extendable billiard cue as claimed in claim 1, wherein said pull bar has an index for angular indication; said butt has another index corresponding to the index of said pull bar for angular indication.
 7. The extendable billiard cue as claimed in claim 1, wherein the positioning device of said stem comprises at least one stop block protruded from the periphery thereof.
 8. The extendable billiard cue as claimed in claim 1, wherein the front positioning device and rear positioning device of said sleeve each comprise at least two inside flanges inwardly protruding from an inside wall thereof. 